.bg{
    width: 100vw;
    height: 100vh;
    .login{
        width: 300px;
        height: 300px;
        border: 1px solid red;
        position: fixed;
        top: 20%;
        left: 40%;
        input{
            margin: 20px ;
        }
        button{
            width: 70px;
            margin: 30px 40%;
        }
    }
}